The invention relates to a topical composition, a topical composition precursor, and methods for manufacturing and using the topical composition and the composition precursor.
Naturally occurring and synthetic polymers have been used in pharmaceutical and cosmetic preparations for several decades. Polymers that have been used in pharmaceutical and cosmetic preparations include hydrophilic polymers, hydrophobic polymers, and polymers having hydrophilic and hydrophobic properties. Hydrophilic polymers are often used as thickeners and/or film formers. Hydrophobic polymers are often used because of their ability to hold active ingredients and to bind to skin.
Compositions have been developed for enhancing the cutaneous penetration of topically or transdermally delivered pharmacologically active agents. For example, see U.S. Pat. Nos. 5,045,317; 5,051,260; and 4,971,800.
A topical composition, a topical composition precursor, and methods for manufacturing and using a topical composition and a topical composition precursor are provided by the invention. The topical composition can be referred to as a xe2x80x9cdelivery systemxe2x80x9d when it is used to promote the delivery of active ingredients to skin tissue. When provided as a use solution, the topical composition has an ability to adhere or bind to skin tissue and thereby hold active ingredients in proximity to skin tissue. In addition, the topical composition has an ability to hold or contain active ingredients so that the active ingredients can be made available to skin tissue when the topical composition is applied to skin tissue. Active ingredients that can be used include natural and synthetic substances that produce a desired effect when placed on skin tissue and may include medicines or drugs or other substances intended for the diagnosis, cure, mitigation, treatment, or prevention of a disease or condition, and may include substances that may be characterized as protectants, repellants, and moisturizers.
The topical composition precursor of the invention can be provided as a result of melt processing a hydrophobic polymer composition and a hydrophilic polymer composition in the presence of less than about 1 wt. % water. The hydrophobic polymer composition includes a poly(vinylpyrrolidone/alkylene) polymer wherein the alkylene group contains at least about 10 carbon atoms. The hydrophilic polymer composition includes at least one of a hydrophilic polymer comprising repeating carboxylic acid groups and/or repeating hydroxyl groups. Exemplary hydrophilic polymers include polyacrylic acid having a weight average molecular weight of at least about 50,000 and exhibiting less than 1% cross-linking, poly(maleic acid/methylvinylether) copolymer having a weight average molecular weight of at least about 50,000, starch, derivatives of starch, cellulose, derivatives of cellulose, carboxymethyl cellulose, polyvinyl alcohol, cyclodextrins, dextrans, and mixtures thereof. The hydrophilic polymer composition can include polyacrylic acid having a weight average molecular weight of between about 50,000 and about 4,000,000, and exhibits less than 1% cross-linking and/or poly(maleic acid/methylvinylether) copolymer having a weight average molecular weight of between about 50,000 and about 4,000,000.
The hydrophobic polymer composition can include a mixture of different poly(vinylpyrrolidone/alkylene) polymers. When the hydrophobic polymer composition contains a mixture of two different poly(vinylpyrrolidone/alkylene) polymers, the first poly(vinylpyrrolidone/alkylene) polymer can be provided at a concentration of between about 5 wt. % and about 54 wt. %, based on the weight of the hydrophobic polymer composition. In addition, the second poly(vinylpyrrolidone/alkylene) polymer can be provided at a concentration of between about 46 wt. % and about 95 wt. %, based on the weight of the hydrophobic polymer composition. Exemplary poly(vinylpyrrolidone/alkylene) polymers include poly(vinylpyrrolidone/1-eicosene) polymer and poly(vinylpyrrolidone/hexadecene).
The topical composition precursor can be formed by mixing the hydrophobic polymer composition and the hydrophilic polymer composition in a melt and providing a functional group parity between the pyrrolidone groups of the hydrophobic polymer composition and the combination of carboxylic acid groups and/or hydroxyl groups of the hydrophilic polymer composition that is between about 1:1 and about 5:1, and can be between about 1.5:1 and about 3:1. For certain compositions, it is expected that this functional group parity of the hydrophobic polymer composition to the hydrophilic polymer composition will result in a topical composition precursor containing about 72 wt. % to about 98 wt. % hydrophobic polymer composition and about 2 wt. % to about 25 wt. % hydrophilic polymer composition, based on the total weight of the topical composition precursor.
A topical composition is provided according to the invention. The topical composition can include the topical composition precursor and can include a result of diluting the topical composition precursor with water. The topical composition preferably includes a result of hydrating the topical composition precursor with water to provide at least about 30 wt. % water. The topical composition can be characterized as a concentrate if it contains between about 30 wt. % and about 70 wt. % water based on the weight of the topical composition. It is expected that the concentrate will be provided with a water concentration of between about 30 wt. % and about 45 wt. % to reduce costs associated with shipping water. When the topical composition is provided as a use solution for application to skin tissue, it is expected that the composition will contain at least about 70 wt. % water and can include between about 70 wt. % and about 96 wt. % water, based on the weight of the topical composition.
The topical composition can include active ingredients such as antimicrobials, antifungals, anti-inflammatory agents, anti-viral agents, drugs, sunscreens, vitamins, alpha-hydroxy acids, surfactants, dyes, fragrances and pigments.
The topical composition can include a surfactant or a mixture of surfactants to enhance the stability of the topical composition and/or to enhance the rate of release of active ingredients. Exemplary surfactants that can be used according to the invention include nonionic surfactants, anionic surfactants, cationic surfactants, amphoteric surfactants, and mixtures thereof. Exemplary nonionic surfactants that can be used according to the invention include ethoxylated surfactants, propoxylated surfactants, and ethoxylated-propoxylated surfactants. An exemplary ethoxylated surfactant includes nonylphenol ethoxylate having about nine ethylene oxide repeating groups. The surfactant component can be incorporated into the topical composition in an amount sufficient to provide the desired stability and the desirable rate of release of active ingredients. In most applications, it is expected that the surfactant will be provided in an amount of up to about 5 wt. %, and will more likely be provided in an amount of between about 0.5 wt. % and about 5 wt. %.
A method for manufacturing a topical composition is provided according to the invention. The method includes a step of melt processing a mixture of a hydrophobic polymer composition and a hydrophilic polymer composition to provide a topical composition precursor, and diluting the topical composition precursor to provide a concentrate having a water concentration of at least about 30 wt. %, based on the weight of the topical composition. The step of melt processing preferably includes mixing the hydrophobic polymer composition and the hydrophilic polymer composition at a temperature of greater than 50xc2x0 C., and more preferably greater than about 125xc2x0 C. The step of melt processing preferably includes mixing the hydrophobic polymer composition and the hydrophilic polymer composition at a water concentration of less than about 1 wt. %.
A method for using a topical composition is provided according to the invention. The method includes applying the topical composition to skin tissue.